Imagine an electronic medical device implanted inside you that monitors your temperature for signs of infection after surgery, then melts away. Or a wireless environmental sensor that decomposes without harming any living creature. Or a phone that you can toss on the compost heap as soon as a newer version hits stores. These devices are closer to reality, because researchers have created degradable electronics that function for a set time—and then dissolve. The work is in the journal Science. [Suk-Won Hwang et al., A Physically Transient Form of Silicon Electronics]

Silicon compounds, the basis of many electronic devices, will eventually degrade in water or bodily fluids. But the process takes hundreds of years. To speed it up, scientists built devices out of extremely thin layers of silicon, along with magnesium, which is naturally found in the human body. These items can quickly fade away in even small volumes of water.

To control the rate the devices disappeared, they were coated in layers of protective silk. The more silk, the longer the transient electronics will last.

Just think of the commercials: “Buy the newest iPhone—before it disappears!”